The Verdehr Trio is a first-rate chamber group with a difference. The instruments -- violin (Walter Verdehr), clarinet (Elsa Ludewig-Verdehr) and piano (Silvia Roederer) -- make unlikely bedfellows. Yet the three have been winning celebrity over 30 years for creating a new niche in world music, commissioning 170-plus works by an international bevy of composers.

Their adventuresome concert Sunday at the Phillips Collection rolled out four recent pieces, three from the 21st century. Things began with an obligatory salute to the 250th anniversary of Mozart's birth: a dance-suite arrangement reflecting Mozart's many-sided personality, not least his bumptiousness. The Verdehr gave it impeccably matched phrasing and contrasting tonal colors as clearly etched as Mozart's operatic characters.

Composer Margaret Brouwer, present for her impressive Trio, said it was inspired structurally by chaos theory. Formal elements, audibly imperceptible on one hearing, tended to vanish into a virtual black hole, although each movement cogently captured a state of mind (even if with well-worn sound effects like plucked piano). The keenly neurotic finale swarmed with a fabric of trills as dense as hordes of mosquitoes.

A sumptuously delivered Trio by Gian Carlo Menotti was followed by Akane Tsuji-Nakanishi's "Songs," a visionary series of compact vignettes based stylistically on Japanese haiku, dadaist verse and other poetry. Each "scene" flowed into the next with powerful momentum and delicate sonorities.

The best piece of the day was Bright Sheng's "Tibetan Dance," a delicate essay in microtones and percussive drive energetically delivered by the Verdehr.

-- Cecelia Porter

Smithsonian Chamber Orchestra

Aperiod-instrument orchestra playing Shostakovich -- sounds like the stuff of a New Yorker satire, right? Well, as it happens, the Smithsonian Chamber Orchestra did just that at the Renwick Gallery on Sunday evening, and made a jaw-dropping success of it.

The piece was Shostakovich's Chamber Symphony (Rudolf Barshai's string orchestra arrangement of the composer's 1960 String Quartet No. 8), and the 18 musicians of the orchestra used 17th-to-19th-century string instruments from the Smithsonian's musical instrument collection, all outfitted with gut strings and played with minimal vibrato. The keening violins and throaty violas, the sinewy, dark-grained lower strings -- all emphasized the trenchancy in Shostakovich's writing, while bringing an almost physical, human immediacy to its tone of mourning. Conductor Kenneth Slowik's reading showed a deep understanding of the music's emotional trajectory.

Mahler's string orchestra arrangement of Schubert's "Death and the Maiden" Quartet proved an edge-of-the-seat experience. Slowik honored the inflated scale of Mahler's arrangement with saturated string tones and a Beethovenian sense of drama when called for, but suggested the intimacy and heartbreak of Schubert's original with just as much success -- and his orchestra produced some ravishing sounds.

Slowik's own orchestrations of Schubert's songs "Erlkonig" and "Death and the Maiden" (both vividly characterized by soprano Linda Mabbs) were, respectively, operatically thrilling and starkly moving, the latter scored for only a hushed complement of cellos. An outstanding concert.